Tuesday, 23 September 2014

Oreos, Candies, Chocolate and Chocolate Milk

Sometimes life gets in the way of blogging so this post has morphed over the past week. One of my goals this semester is to add activities to my grade 10 academic class. Here is how things have played out for the first unit on solving systems of linear equations.I wrote about how I changed my introduction to solving systems by elimination here. The next day they worked on the Oreo problem. I stole this from Nathan Kraft (here) which is why I haven't blogged about it myself. I introduced this activity last year and since it is awesome, I continue to use it. Students have to figure out whether the wafers or cream centre of an Oreo has more calories. (But really, you must read Nathan's intro to this.) Here is the information they are presented with in order to solve:

They worked on the big whiteboards and some even presented their solutions to the class. Note that Canadian Oreo packages have 2 cookies per serving for both regular cookies and Double Stuf cookies, which is not nearly as interesting as the ones shown. I tell the kids this once they have answered the question. And, yes, I do bring in Oreos for them.I also added in a candy lab when we got to solving word problems. I stole this from someone who posted on Twitter. I sent myself the link but it didn't have a name associated with it, nor does the Google doc. If someone knows to whom I should attribute credit, please let me know! I started the class like this:

They were fairly (!) excited when they saw the word candy last period on a Friday afternoon. I randomly picked names from my tin of popsicle sticks to make groups of 4. Each group received a brown paper bag upon which I had written a letter and a number. The letter identified the bag and the number indicated the total number of candies and chocolates in the bag. I borrowed kitchen scales from our science department (thank you!) so that they could weigh their bag of candy. I wrote the mass of 1 candy (7 g), 1 chocolate (13 g) and an empty bag (8 g) on the board. And they were off! They did good work and once they had an answer we did the reveal - I opened the bag and counted out the candies and chocolates. They weren't perfect, but they were close and their work was excellent. I also had a few more challenging bags that had candies, chocolates and granola bars in them with an additional hint written on the bag. I will add pictures...sometime! As a side note, a greater total mass in the bag led to a better result. For next time...Next in the word problem collection were mixture problems. My students have always found mixture problems to be particularly confounding. I thought I would use a demo to help (the idea, again, stolen from the Internet). A litre of milk appeared along with chocolate syrup, and the excitement was palpable!

I told them that Noah only put 1 tablespoon (15 ml) of chocolate syrup with 250 ml of milk, while Isabelle puts 4 Tbs of chocolate syrup for the same volume of milk. (This is a lie. They would both put as much chocolate syrup as they could.) I made their respective chocolate milks for the class and showed them to all the students. They could see the difference between the two as one was much darker than the other. We calculated the percent of chocolate syrup for each. Then the question:

Fake context for sure. Jacob would want more chocolate syrup than Isabelle and Noah put together! But my students were engaged. They were paying attention. They, for the most part, wanted to know how to do this. And we did. Then, they worked through one more on their own:

I find that I am not worried about time, despite having to stick to a pretty regimented schedule. I believe that it is better to do one example where are all students engaged rather than 3 traditional ones where several (many?) of the class is not really paying attention.What else have I changed? Homework. I do give homework in this class (but not in grade 10 applied math), which I check daily for completion. I believe that some practice is important in consolidating the material we have (un)covered and hopefully a deeper understanding can be developed, at least some of the time. But while looking for midpoint activities I found an old post from Dan Meyer about homework (or not giving homework) which included a suggestion from someone about modifying how homework is assigned. I liked the idea so implemented it the following morning. I am breaking up homework into basic, regular and challenge questions and have asked students to do 2 of the sets. The students who are confident with what was done in class can start with the regular set and move on to the challenge questions. Those who are a little less solid on the material start with the basic questions and then do the regular. It looks something like this:

I still think there is too much homework there, but I am working on that. The feedback I have received from students has been positive. I did feel the need to point out that after doing the regular set, students should not do the basic set in order to avoid the challenge questions!Overall, I think I have made some positive changes. Not a huge overhaul like I did with grade 10 applied last year, but a move in the right direction nonetheless.